title: Targeted disruption of py235ebp-1: invasion of erythrocytes by Plasmodium yoelii using an alternative Py235 erythrocyte binding protein.
abstract: Plasmodium yoelii YM asexual blood stage parasites express multiple members of the py235 gene family, part of the super-family of genes including those coding for Plasmodium vivax reticulocyte binding proteins and Plasmodium falciparum RH proteins. We previously identified a Py235 erythrocyte binding protein (Py235EBP-1, encoded by the PY01365 gene) that is recognized by protective mAb 25.77. Proteins recognized by a second protective mAb 25.37 have been identified by mass spectrometry and are encoded by two genes, PY01185 and PY05995/PY03534. We deleted the PY01365 gene and examined the phenotype. The expression of the members of the py235 family in both the WT and gene deletion parasites was measured by quantitative RT-PCR and RNA-Seq. py235ebp-1 expression was undetectable in the knockout parasite, but transcription of other members of the family was essentially unaffected. The knockout parasites continued to react with mAb 25.77; and the 25.77-binding proteins in these parasites were the PY01185 and PY05995/PY03534 products. The PY01185 product was also identified as erythrocyte binding. There was no clear change in erythrocyte invasion profile suggesting that the PY01185 gene product (designated PY235EBP-2) is able to fulfill the role of EBP-1 by serving as an invasion ligand although the molecular details of its interaction with erythrocytes have not been examined. The PY01365, PY01185, and PY05995/PY03534 genes are part of a distinct subset of the py235 family. In P. falciparum, the RH protein genes are under epigenetic control and expression correlates with binding to distinct erythrocyte receptors and specific invasion pathways, whereas in P. yoelii YM all the genes are expressed and deletion of one does not result in upregulation of another. We propose that simultaneous expression of multiple Py235 ligands enables invasion of a wide range of host erythrocytes even in the presence of antibodies to one or more of the proteins and that this functional redundancy at the protein level gives the parasite phenotypic plasticity in the absence of differences in gene expression.
authors.affiliation: Division of Parasitology, MRC National Institute for Medical Research, London, UK. sogun@nimr.mrc.ac.uk
authors.forename: Solabomi A
authors.initials: SA
authors.lastname: Ogun
authors.forename: Rita
authors.initials: R
authors.lastname: Tewari
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Otto
authors.forename: Steven A
authors.initials: SA
authors.lastname: Howell
authors.forename: Ellen
authors.initials: E
authors.lastname: Knuepfer
authors.forename: Deirdre A
authors.initials: DA
authors.lastname: Cunningham
authors.forename: Zhengyao
authors.initials: Z
authors.lastname: Xu
authors.forename: Arnab
authors.initials: A
authors.lastname: Pain
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Holder
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan / Q000235:genetics*; D015139:Blotting, Southern; D015153:Blotting, Western; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000276:immunology / Q000378:metabolism / Q000469:parasitology*; D005455:Fluorescent Antibody Technique; D017353:Gene Deletion; D018503:Genome, Protozoan; D047468:Immunoprecipitation; D008288:Malaria / Q000235:genetics* / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D005810:Multigene Family; D010967:Plasmodium yoelii / Q000235:genetics / Q000254:growth & development* / Q000472:pathogenicity*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan; D012333:RNA, Messenger